Neutral particle beam (NPB) technology has been developing for some time. A NPB system consists of: (1) a negative ion source; (2) a low energy transport system; (3) a high energy accelerator system; (4) beam optics; (5) a neutralizer; (6) a neutral beam sensing system; and (7) a suitable Acquisition Tracking and Pointing (ATF) system. The particles must have a charge for the accelerator to operate. The ions are given a negative charge because it is much easier to remote the loosely bound extra electron than it is to add an electron to high energy positive ions. There are two primary ways of removing the extra electron from the negative ions. One of the simplest neutralizers is the collisional type, which utilizes a low density gas or a very thin foil to remove the excess electron. This process has two limitations; (1) it introduces divergence system loss of efficiency, and (2) the maximum efficiency of the process is approximately 60%, i.e. 20% remain negative, 20% become positive and 60% are neutralized. If the foil is made thicker, more of the ions are double stripped, and if the foil is made thinner more of the ions are not stripped or neutralized. The effective efficiency of this system is approximately 20 to 30%. The second method of neutralizing high power beams utilizes a high power laser beam. This technique results in high percentage neutralization and a low induced divergence. This process relies on the photons interacting with a loosely bound electron with sufficient energy to eject the electron. The major laser and high mirror reflectivity necessary to confine the photons until they interact with the beam. The weight and power requirements for the laser are presently about the same as the rest of the neutral particle beam platform. This is still potentially of benefit to the overall system since it could result in almost a factor of four increase in the accelerator effective efficiency.
Even with the prior developments, there is still a need for improvements in this area of particle beam neutralization.
Accordingly, it is an object of this invention to provide a non-coherent photon source for neutralizing ions or the particle beam.
Another object of this invention is to provide non-coherent photon neutralization which can yield neutralization efficiency as the laser with only slight increase in beam divergence over an optimized laser neutralizer.
Still another object of this invention is to provide a non-coherent photon neutralization source that has high efficiency photon production with an efficiency as high as 30 to 50%.
Other objects and advantages of this invention will be obvious to those skilled in this art.